Urea dihalides and process for the production thereof



United States Patent 3,117,997 UREA DIHALIDES AND PROCESS FOR THE PRODUCTION THEREOF Engelbert Kiihle, fiologne-Stammheim, Richard Wegler, Leverkusen, and Ludwig Eue, Cologne-Mulheim, Germany, assignors to Farhenfabriken Bayer Aktiengesellschaft, Leverkusen, Germany, a corporation of Germany No Drawing. Filed Jan. '11, 1961, Ser. No. 31,931 Claims priority, application Germany Jan. 19, 1960 7 Claims. (Cl. 260-5705) The present invention relates to and has as its objects new and useful herbicidal active urea dihalides of the general formula and processes for their preparations.

in the above formula R stands for an optionally substituted aromatic radical, R R and R denote hydrogen, optionally substituted alkyl or aryl radicals, and X represents chlorine or bromine, these being the halogens having an atomic number from 17 to 35.

A preferred method to make these compounds consists in reacting corresponding ureas with phosphorus-pentahalides as is to be seen from the following reaction scheme:

The symbols here have the same significance as said above.

Ureas suitable for this reaction are, for example, N- phenyl-l '-rnethyl urea, lN-phenyl-NflN dimethyl urea, N- (4-chlorophenyl)-N, l '-dibutyl urea, N,N-diphenyl-N methyl urea and the like.

The reaction which in general proceeds exothermically is advantageously carried out at room temperature or at most at slightly elevated temperatures. Preferably an inert organic solvent such as carbon tetrachloride, chlorobenzene or dichloro-benzene is used for control of the reaction. In some cases, it is especially advantageous to use as solvent phosphorus oxychloride which is also formed in the above reaction.

Another method to prepare the inventive compounds is to add hydrogenhaiides to u-haloformamidines which are known, e.g., from copending application U.S. Serial No. 28,555 or also from Belgian patent specification 585,681.

This reaction may be represented by the following equation as it is to be seen R of the above formula will be hydrogen in the instant case. The other symbols have the same significance as said before. Also this reaction optionally is carried out in inert organic solvents, especially those mentioned above.

The new compounds may be used as intermediates for further syntheses. They possess, moreover, a herbicidal action. When used in this way, they are preferably applied in a mixture with inert materials such as talc or kaolin, inter alia.

The inventively new compounds exhibit the same way of action and may be used against the same weeds as the known commercial urea herbicides such as Monuson which is 3-(para-chlorophenyl)-l,l-dimethyl urea, Diuron 3,117,997 Patented Jan. 14, 1964 which is 3-(3,4-dichlorophenyl)-1,l-dimethyl urea; and the like.

The following examples are given for the purpose of illustrating the invention.

Into a suspension of g. of phosphorus pentachloride in ml. of POCl 115 g. of N-(4-chlorophenyl)- N',N'-dimethyl urea are introduced in small portions. With a temperature rise up to about 35 C., dissolution slowly sets in. The solution is heated on the water bath, whereby crystallisation sets in at about 80 C. After stirring the mass in the hot for about 1 hour, it is filtered ofi with suction when cold and then washed with benzene. 128 g. of the dichloride of M.P. 18819l C. (decomposi tion) are obtained.

When N-(4-chlorophenyl)-N,N',N'-trimethyl urea is used as starting material, the urea dichloride of the formula By the same way there may be obtained the following compounds compounds:

0 nao@-nn o N Cl C1 Cl OzHs 3 4 We claim: and R is a lower alkyl radical having up to 4 carbon 1. A compound of the general formula atoms.

R R 5. The compound of the following formula 3 NC-N 5 R; X X R; C1 C1 CH3 wherein R stands for a member selected from the group The compound of the following formula consisting of phenyl and chlorophenyl groups, R denotes C1 C1 CH 2. member selected from the group consisting of hydrogen 0 3 and lower alkyl radicals up to 4 carbon atoms, R and R stand for lower alkyl radicals up to 4 carbon atoms and CH3 CH3 X represents halogen having an atomic number from 17 7. The compound of the following formula to 35.

2. A compound of claim 1 wherein R is phenyl and 15 R is hydrogen. 7

3. A compound of claim 1 wherein R is chlorophenyl 01 c1 CH and R is hydrogen.

4. A compound. of claim 1 wherein R is chlorophenyl No references cited- 

1. A COMPOUND OF THE GENERAL FORMULA 